Anatase Ti\(_{1-x}\) Co\(_x\) O\(_{2-\delta }\)  epitaxial thin films with \(x\)  = 0.05 were synthesized by the pulsed laser deposition method on LaAlO\(_3\)  (001) substrates at 523 K and oxygen pressures (\(P_{{\rm O}_2}\) ) of 5 \(\times \)  \(10^{-7}\) , 1 \(\times \)  \(10^{-6}\)  and 2 \(\times \)  \(10^{-6}\)  Torr. The resistivity increases in this order and these samples are hereafter referred to metallic, intermediate, insulating samples, respectively. The carrier densities \(n_e\)  were 4.1 \(\times \)  \(10^{19}\) , 1.1 \(\times \)  \(10^{19}\)  and 4.0 \(\times \)  \(10^{18}\)  cm\(^{-3}\) , respectively. Segregation of secondary phases were not observed under careful inspections by x-ray diffraction (XRD) and transmission electron microscopy (TEM) [1]} of \(\sim \) 40 nm thick films [1]}. Reflection high-energy electron diffraction was monitored during the in-situ growth. An intensity oscillation was observed at the initial stage of the growth. We have confirmed that Co distribution along the film thickness direction in our films is uniform using TEM [1]}, unlike the inhomogeneous distribution in films prepared on Si demonstrated using atom probe tomography by Larde et al [4]}. Ferromagnetism at room temperature was confirmed by Hall-effect measurements and magnetization measurements. XAS and XMCD measurements were performed at the BL-11A beamline of the National Synchrotron Radiation Research Center, Taiwan. In XMCD measurements, magnetic fields (H) were applied parallel to the direction of anatase (001). XAS and XMCD spectra were obtained in the TEY and TFY modes and probing depths were \(\sim \) 5 and 100 nm, respectively.
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